1. Field of the Invention
The present invention relates to a malleolar implant for a partial or total prosthesis of the ankle and to an ancillary tool for placing such an implant.
2. Brief Description of the Related Art
It is known, for example from EP-A-O 864 304, to fit an ankle prosthesis with a malleolar implant that bears against an articular surface of the astragalus, whether it be a natural surface or of a surface of a prosthetic component. During an operation on an ankle, access to the internal articular surfaces is limited by the ligamentary system that does not necessarily allow a sufficient dislocation of the joint. In particular, access to the internal surface of the fibular malleolus may be insufficient, which induces difficulties in positioning the implant, particularly by impaction.
With reference to the embodiments of FIGS. 4 and 5, it is disclosed in EP-A-O 864 304 to introduce an implant from the outer face of the fibula. However, this necessarily limits the surface of the head of this implant, which must be less than or equal to the surface of the orifice provided in the bone, so that it is necessarily of relatively small dimensions with the result that the malleolus is fragile.
For the foregoing reasons, the positioning of the malleolar implants in the known prostheses is not entirely satisfactory.